1. Field of the Invention
The present invention relates to a power supply device having improved output efficiency in a light load region.
2. Description of the Related Art
Generally, in order to drive an electronic apparatus, a power supply device supplying driving power required for driving is required.
Among power supply devices, a resonance type LLC direct current-to-direct current (DC/DC) converter may supply a predetermined amount of power to a load according to frequency using resonance characteristics. However, in the case in which the LLC DC/DC converter supplies the power to a light load, the LLC DC/DC converter is controlled in a high frequency region. That is, in the light load region, as a control frequency of the LLC DC/DC converter is increased, switching loss of a switching element may be sharply increased and loss caused by alternating current impedance may be increased due to skin effect occurring in a transformer, a coil, or the like.
The following related art documents 1 and 2 disclose a method of driving a light load, but do not disclose a switching control method corresponding to that suggested in the present disclosure.